Electron transfer in self-assembled orthogonal structures

J Phys Chem A. 2006 Jul 6;110(26):7994-8002. doi: 10.1021/jp054992c.


Two new molecular dyads, comprising pyrromethene (bodipy) and 2,2':6',2"-terpyridine (terpy) subunits, have been synthesized and fully characterized. Absorption and fluorescence spectral profiles are dominated by contributions from the bodipy unit. Zinc(II) cations bind to the vacant terpy ligand to form both 1:1 and 1:2 (cation:ligand) complexes, as evidenced by X-ray structural data, NMR and spectrophotometric titrations. Attachment of the cations is accompanied by a substantial decrease in fluorescence from the bodipy chromophore due to intramolecular electron transfer across the orthogonal structure. At low temperature, nuclear tunneling occurs and the rate of electron transfer is essentially activationless. However, activated electron transfer is seen at higher temperatures and allows calculation of the corresponding reorganization energy and electronic coupling matrix element. In both cases, charge recombination is faster than charge separation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Boron Compounds* / chemical synthesis
  • Boron Compounds* / chemistry
  • Chelating Agents* / chemical synthesis
  • Chelating Agents* / chemistry
  • Crystallography, X-Ray
  • Electron Transport
  • Fluorescent Dyes* / chemical synthesis
  • Fluorescent Dyes* / chemistry
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Structure
  • Pyridines* / chemical synthesis
  • Pyridines* / chemistry
  • Spectrophotometry
  • Zinc / chemistry*


  • 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene
  • Boron Compounds
  • Chelating Agents
  • Fluorescent Dyes
  • Pyridines
  • Zinc